Abstract:
In this paper, the prospective of using organic nanostructured crystals of p – type
TTT2I3 (tetrathiotetracene-iodide) and n – type TTT(TCNQ)2 (tetrathiotetracene-iodidetetracyanoquinodimethan)
as components of thermoelectric biosensors is investigated. A
thermoelectric biosensor consists of a p-n module, specially designed to be used as power
generator, converting human body heat into small electrical signals, or as local cooler,
able to create low temperatures (up to -20 oC) on small surfaces. In biomedical
applications, the temperature gradients are low and, in order to obtain as much as possible
high electrical signal, materials with enhanced thermoelectric properties are required.
Organic crystals of TTT2I3 and TTT(TCNQ)2 were investigated earlier and it was
established that these organic compounds are prospective thermoelectric materials if an
appropriate optimization of carrier concentration with further purification of the crystal is
performed during synthesis. In the following, the electrical conductivity, thermopower
(Seebeck coefficient) and the delivered voltage from a p-n module constructed from the
mentioned crystals are calculated for different crystals parameters at room temperature. It
is established that a single p-n module made of organic crystals can deliver up to 5 mV
under a temperature difference of 20 K around the room temperature if optimization
procedures are applied.